This invention relates to a system for hot extruding, molding, drawing, and similarly processing plastomers or elastomers, incorporating a means of recovering and utilizing heated air from the cooling of parts which undergo or are subjected to heating.
As is known, some machinery for processing plastomeric or elastomeric materials require both the application of heat, for properly softening the material, and a supply of cold air (or other fluid) to promote maintenance of an optimum temperature in the heated parts.
This is a typical requirements of extruder and drawing machine cylinders, wherein heating is accomplished by means of electric thermal units having coaxial interspaces, wherethrough ventilating air is blown as required to prevent the cylinder temperature from exceeding preset values.
Said ventilating air, of course, is exhausted from the electric thermal units to carry away a given amount of heat which, with conventional systems, is usually discharged to the atmosphere.
On the other hand, it is also known that some components of such systems require to be heated or preheated.
This heat is applied, according to current practice, by employing separated heat sources, which results in a not negligible increase of operating cost.